“Common variable immunodeficiency” is a pathology which results in the body’s inability to defend itself against infections due to a lack of immunoglobulin G. It increases the risk of cancer.
Definition: what is it?
Common variable immunodeficiency (CVID or CVID in English for “Common Variable Immune Deficiency”) is the most common of primary immune deficiencies, i.e. immune deficiencies which are not secondary to another pathology nor linked to an external event. CVID occurs without finding an explanatory cause most of the time, even if in a relatively small proportion, one can identify a genetic cause. This pathology is characterized by immunoglobulin G deficiency Who is here main class of antibodies in the blood. “In other words, this means thatthe individual lacks certain elements of the immune system to be able to defend itself against infections but also to allow the immune system to avoid getting out of control in the event of autoimmune diseases. In cases of common variable immunodeficiency (as in many other primary immune deficiencies), the two can be associated“, specifies Dr Nizar Mahlaoui, pediatrician and co-head of the reference center for hereditary immune deficiencies in children and adults (CEREDIH) at the Necker-Enfants Malades university hospital.
In France, 2,500 people are known to have CVID
What are the symptoms ?
CVID can manifest itself according to several categories of symptoms:
- Of the repeated but relatively trivial infections : sinusitis, ear infections, bronchitis… The patient experiences several of them during the year but almost systematic antibiotic treatment is enough to reduce their frequency.
- Of the more severe infections : pneumonia, meningitis, septicemia, and other potentially fatal infections.
- Of the non-infectious manifestations : autoimmune manifestations (women are more represented than men in the general population), granuloma, inflammatory digestive or pulmonary damage.
- Of the allergic manifestations : there are no specific allergies (many types of allergies can be observed).
Ultimately, there is a greater risk than the population at the same age of developing cancer (especially cancers of the blood (leukemia) or lymph nodes (lymphoma) but it also happens that there are more organ cancers such as cancer of the digestive tract).
Most often, CVID is diagnosed in adolescents, young adults or mature adults. It is suspected in infectious but also non-infectious manifestations, which requires performing the blood assay for immunoglobulins (IgG, IgA and IgM) in addition to serum protein electrophoresis. A low level of IgG associated with a low level of Iga and/or IgM guides the diagnosis. Often, this is associated with a reduction or even an absence of response to vaccination (tetanus for example). Before the age of 4, this diagnosis cannot be made and other causes of primary/hereditary immune deficiency should be sought. “CVID affects women as much as men and people of European descent much more than people of African origin. In France, 2,500 people are now known to have CVID“, comments the specialist.
Is that bad ? What effect on life expectancy?
Scientific epidemiological work has shown that there are two categories of CVID:
► CVID which will “only” lead to infectious manifestations, in which case life expectancy is comparable to the general population among Western women.
► The DICV which is responsible for more serious non-infectious complications such as autoimmune diseases or inflammatory lung damage have a negative impact on life expectancy. From the age of 40-50, the life expectancy of these patients decreases.
What are the treatments ?
Overall, support is divided into three groups:
► Either the table is relatively simple, in which case treatment is based on monitoring in consultation with the specialist immunologist once a year.
► If the patient has very frequent infections in winter but he is fine the rest of the year, preventive treatment of these infections can be offered to him by administering a small dose of antibiotics every day during the winter (BACTRIM® or azithromycin). This allows patients to significantly reduce these infections and even survive the winter almost unscathed.
► If the patient has had very severe infections, associated with a very low level of immunoglobulin G in the blood, we cannot leave only a small dose of antibiotic, he must be given the immunoglobulins he is missing via an infusion in the hospital or at home, intravenously or subcutaneously. This treatment will have to be followed for many years or even for life because when the immune system is altered and almost never recovers. This treatment allows you to lead a more or less normal life.
This support must be done in a CEREDIH National Reference Center (Reference Center for Hereditary Immune Deficiencies). “Depending on the patient’s clinical history and examinations, including the blood test and assessment of lesions (pulmonary, ENT, etc.), theThe referring doctor will define the appropriate treatment“, indicates Dr Nizar Mahlaoui. The follow-up is multidisciplinary: pulmonologist, ENT, gastroenterologist, dermatologist, endocrinologist.
Thanks to Dr Nizar Mahlaoui, pediatrician (pediatric immuno-hematology and rheumatology department) and co-head of the reference center for hereditary immune deficiencies in children and adults (CEREDIH) at theNecker-Enfants Malades university hospital